Histidine deficiency, food intake and growth in normal and walker 256 carcinosarcoma‐bearing rats

Abstract

Male Sprague‐Dawley rats with and without growing Walker 256 tumors were fed 3 isonitrogenous, isoenergetic, semisynthetic diets. The N sources of the 3 diets were casein, a complete free amino acid mixture simulating casein, and the same amino acid mixture but now totally lacking histidine. Tumor‐free rats and host and tumor components of tumor‐bearing rats showed identical growth on the casein and on the casein‐simulating free amino acid diets. Change from complete amino acid diet to histidine‐free diet depressed food intake identically in controls and tumor‐bearers in early stages of tumor growth. In later stages of tumor growth, when tumor‐induced hypophagia had become apparent on the complete diet, the histidine‐free diet had a progressively less depressive effect on food intake in the tumor‐bearers.